Comparison of methods for quantification of myocardial infarct size from delayed enhancement magnetic resonance data

We sought to assess myocardial infarct (MI) volume with different quantitative methods in both acute (AMI) and chronic MI (CMI) from CMR late Gadolinium Enhancement images. CMR exam was performed 50±21 hours after MI in 52 patients and was repeated 100±21 days later in a subgroup of 34 patients. Necrosis volumes were quantified using: 1) manual delineation, 2) automated fuzzy c-means method, and 3) +2 to 6SD thresholding approaches. Results were compared against peak values of serum Troponin I (TnI), creatine kinase (CK) and LV functional parameters. For CMI, quantitative evaluation of infarct size using manual, +2SD, +3SD and fuzzy c-means provided equivalent results for comparisons of MI volumes against LV function parameters (r>;0.79, p<;0.0001). For AMI, +2SD and fuzzy c-means approaches provided higher correlations for comparisons of AMI volumes against biochemical markers (r>;0.77, p<;0.0001) and chronic LV function parameters (r>;0.59, p<;0.0002). The fuzzy c-means and +2SD methods provided highest correlations with biochemical MI quantification as well as LV function parameters. The fuzzy c-means approach which does not require an arbitrary identification of the remote myocardium is fast and reproducible. It may be clinically useful in the evaluation of patients with MI.